Compressor shut-off valve mechanism



the rear of valve memberl 26]. The groove is also in communication with chamber-I3 by means of a slot 31 which is adapted to be controlled by a valve element in theform of'a4 sealing cup 36 carried by the end 'of projection 32. vThe construction is such that when piston 3| is in a position wherein the sealing cup is to the right oi' slot 31, as shown in Figure 2, communication is permitted between chamber I3 and the chamber at the rear of valve member 26 by way of passage 36. When the sealing cup is inthis position, it prevents communication from chamber I8 to chamber I9 by way of clearance 313. When the piston is moved forwardly so the sealing element 33 is at the left of slot 31, communication is established between the chamber at the rear of valve member 26 and chamber i|9 byway of passage 36, groove 35. slot 31, and clearance 33. Provision is also made by means of aport 39 to connect chamber I9 at the left of piston 3| with the atmosphere. The left end of chamber I3 is in communication at all times with the dome of thecompressor by means of conduit 46. l

The piston 3| is provided with a sealing element 4I and chamber I9 at` the right ofthe piston is connected by a passage 42 and a conduit 43 to conduit |2 at a point between control valve I4 and fluid motor I3. The piston 3| is normally biased by a spring 44 positioned between the piston and a plug 45 closing the right end of chamber I9. Th plug also carries an adjusting mechanism 46 for varying the tensiumnv of spring 44.

Spring 44 in the mechanism shown is so de'- signed and adjusted to exert such a force on piston 3| that this piston will be moved to the left and maintained in this position as long as the pressure in the dome and also chamber I3 at the left of the sealing element 33 is less than one hundred pounds per square inch. When piston 3| is in its left-hand position all `of the sealing element 33 will be positioned to the left of slot 31 and the chamber at the rear of valve member 26 wllfbe connected to theatmosphere by way of passage 36, groove'35, slot 31, clearance 33 and exhaust port 39. Under these conditions, the valve member 26 is maintained in its open position, as shown in Figure 2, by the action of spring .23. Thev compressor, if operating, is now free to draw air in through inlet port 23 and outlet port 24 of the valve casing and after compressing it, force it into tank 3. When the pressure in the dome and the tank reaches a valueof one hundred pounds' per square inch, the pressure 'acting on the sealing element 33 will be sumcient to movel this sealing element and piston 3| to the'right against the action of. spring 44 to the positionshown in Figure 2. As soon as the sealing element 36 assumes its position at the right of slot 31, the compressor dome will be connected to the chamber at the rear of the'valve member 26 and thus force the valve member tot the right against seat 26 shutting off the compressor inlet..

If, after the pressure in the pressure tank reaches one hundred pounds per square inch, the fluid motor-|3 should be connected to the tank by the control valve I4, fluid under pressure will be admitted to chamber I9 at the right'end of 4piston 3| by way of conduit 43 and passage 42,

thereby forcing the piston to the left. This will result in the sealing element 33 being positioned to the left ofl slot 31, therebyconnecting the chamber at'the left end of the valve member 26 with the atmosphere and relieving the pressure,

The spring 23 will now be eiecdome and tank again reaches the value of one hundred pounds per square inch, valve member 26 will be reseated land the compressor shut oi in the manner alreadydescribed, it, of course, being assumed that the pressure acting on piston 3| has been exhausted as a result of exhaustion of the fluid motor by control valve I4. In the bevent the fluid motor is not exhausted, the compressor will not be shut oil but any overcharging ofthe tank is prevented by the relief valve 41.

As a result of leakage, the tank may lose considerable pressure if the uid pressure-actuated motor is not operated for a long period of time. The valve `mechanism disclosed, however, prevents the pressure in the tank from dropping below a predetermined minimum value. I1 the pressure in the dome should drop to a value of around ninety pounds per square inch, spring 44 will become effective to move piston 3| to the j left against what pressure is in chamber I3 at the left of the sealing element 33. When the sealing element is moved to its position at the left of slot 31, pressure in the chamber at the rear of the valve member 26 will bere'lieved, the valve member opened and the compressor permitted to operate to restore the l'one hundred pounds per square inch pressure in Ithe dome and the receiver.

From the foregoing it is apparent that I have provided a control system for a compressor that will automatically unload the compressor when the pressure in the receiver reaches a predetermined value and which will cause the compressor to again become operative to, restore the pressure in the receiver whenever uid under pressure is used therefor. Provision Is also made to prevent the pressure in the receiver from dropping below a given value notwithstanding the uid under pressure may not be used therefrom.

Being aware of the possibility of modiiications in the particular structure herein described without departing from the foundamental principles of my invention, I do not intend that its scopeY be limited except as set forth by the appended claims.

Having fully described my invention, what I claim as new and desire to secure by Letters Patent of lthe United States is:

l. In apparatus of the class described, a fluid compressor provided with an intake port and an exhaust port, a fluid pressure receiver connected to the exhaust port, a fluid pressure-actuatedsystem adapted to be operated by uid pressure from the receiver, means comprising valve mechanism 'for closing the intake of the compressor. and means controlled by fluid pressure employed in the operation of the iiuid pressure-actuated system forcausing the intake of the compressor to be opened. v

2. In apparatus of the class described, a fluid compressor provided with an intake port and an exhaust port, a fluid pressure receiver connected to the exhaust port, a uid pressure-actuated system adapted to be operated by fluid pressure from the receiver, valve mechanism associated- 'with the intake of the compressor, means for automatically operating the valvemechanism to close thef intake by a predetermined pressure `resulting from operation o'f the compressor, and

the operation of the fluid pressure-actuated system for causing the intake of the compressor to be opened.

3. In apparatus of the class described, a uid compressor provided with an intake port and an exhaust port, a uid pressure receiver connected to the exhaust port, a fluid pressure-actuated system adapted to be operated by fluid pressure from the receiver, valve mechanism associated with the intake of the compressor and comprising a movable valve member, resilient means for biasing the valve member to open position, means for moving said .valve member to closed position by a predetermined iiuid pressure, and means controlled by fluid pressure in the uid pressure-actuated system for causing the movable valve member to -assumeopen position.

4. In apparatus of the class described, a iiuid compressor provided withan intake port and an exhaust port, a iuid pressure receiver connected to the exhaust port, a fluid pressure-actuated system adapted to be operated by iiuid pressure from the receiver, vaivemechanism associated with the intake of the compressor and comprising a movable valve member, resilient means for biasing the valve member to open position, means for moving said valve member to closed position when there is a predetermined iiuid pressure in the receiver, and means operable by fluid pressure in the fluid pressure-actuated system for permitting the valve member to assume an open position under the action of the resilient means.

5. In apparatus of the class described, a fluid compressor provided with an intake port and an exhaust port, a fluid pressure receiver connected to the exhaust port, a iiuid pressure-actuated system adapted to be operated by fluid pressure from the receiver, valve mechanism associated with the intake of the compressor and comprising a chamber and a movable valve member therein for controlling the intake of the compressor, a spring for biasing the valve member to open position, means for connecting the chamber to the exhaust side of the compressor whereby a predetermined pressure built up by thecompressor will be eiective to move the valve member to closed position, means forming an exhaust passage from the chamber, and piston valve means associated with the exhaust passage and operable by uid pressure in the uid pressureactuated system for exhausting the chamber.

6. In apparatus of the class described, a fluid compressor provided with an intake port and an" exhaust port, a fluid pressure receiver connected to the exhaust port, a fluid pressure-actuated system adapted to be operated by fluid pressure from the receiver, valve mechanism associated withthe intake of the compressor and comprising a chamber and a movable valve member therein ior controlling the intake of the compressor, a spring for biasing the valve member to open position, conduit means for connecting the chamber to the exhaust side oi the compressor whereby a predetermined pressure built up by the compressor will be effective to move the valve member to closed position. means forming an exhaust passage from the chamber, valve means ier disconnecting the chamber from the exhaust side oi the compressor and connecting the chamber to its exhaust passage, and means for orating said valve means by uid pressure i in the iiuid pressure-actuated system.

7. In apparatus of the class described, a fluid compressor provided with an intake port and an exhaust port, a fluid pressure receiver conr- :nected to the exhaust port, a fluid pressurecommunication between the rst chamber and said conduit means, a spring for biasing the slidable element to a position where the first chamber communicates with the atmosphere,

said slidable element being moved by a predetermined pressure to another position Where the first chamber will be in communication with the exhaust side, and means operable by the iiuid pressure employed in the iluid pressure-actuated system for moving said slidable element to the iirst named position.

8. In valve mechanism of the class described for association with the intake of a compressor and a fluid pressure receiver connected to the exhaust side thereof, a casing having a port for communication with the compressor intake, a movable member adapted to be acted upon by iluid pressure from the exhaust side of the compressor for closing the port, a spring for biasing the member to open position and preventing movement of the member to closed position except When acted upon by a predetermined pressure, means comprising a portion of the movable member and the casing for forming a charnber, means including a passage for connecting the chamber to atmosphere, a valve for controlling said passage, and means operable when the pressure in the receiver is a given value 'for closing said valve.

9. In valve mechanism of the class described for association with the intake of a compressor and a uid pressure receiver connected to the exhaustside thereof, a casing having a port for communication with the compressor intake, a movable member adapted to be acted upon by fluid pressure from the exhaust side f the compressor for closing the port, a spring for biasing the member to open position and preventing movement of the member to closed position except when acted upon by a predetermined pressure, means comprising a portion of the movable member and the casing for forming a chamber, means including a passage for connecting the chamber to atmosphere, a valve for controlling said passage, and means for causing said valve to be opened when the pressure in the receiver drops a predetermined amount below the value ofthe predetermined pressure required to move the movable member.

1G. In valve mechanism of the class described 'for association with the intake of a compressor and a fluid pressure receiver connected to the exhaust side thereof, a casing having a port for communication with the compressor intake, a movable member adapted to be acted upon by fluid pressure from" the exhaust side of the compressor for closing the port, a spring for biasing' the member to open position and preventing movement of the'member to closed position ex- (ifi the intake of the compressor, a movable valve member in said casing for controlling the port, y

a spring for biasing the member to open position, said member a chamber, means comprising a movable ,mem-

ber ior forming a secondl chamber adapted to be v connected with the receiver, a spring acting on the movable memberin the second chamber, a conduit connecting the chambers, a valve for controlling the conduit, and means operable by. a predetermined fluid pressure in the second chamber for causing the movable member therein to move said valve to open position.

l2. In apparatus of the class described, a uid compressor provided with an intake port and an exhaust port, a fluid pressure receiver connected to the exhaust port, a fluid-pressure-actuated system adapted to be operated by iluid pressure from the receiver, valve mechanism associated with the intake of the compressor and comprising a chamberand a movable valve member therein for controlling the intake of the coinpressor, a spring for biasing the valve member to open position, conduit means for connecting the chamber to the exhaust side of the compressor whereby a predetermined pressure built up by the compressor will be effective to move the valve member to closed position, meansv forming an exhaust passage from the chamber, piston valve 'means acted Iupon by iluid pressure in thereceiver for alternately closing and opening the conduit means and the exhaust passage, and a spring for biasing said valve means to a position where the conduit means will be closedl and the exhaust exhaust passage when the pressure built up by the compressor and acting on the piston valve means is a predetermined value'.

13., In apparatus of the classdescribed, a iluid compressor provided with an intake port and an exhaust port, a uid pressure receiverconnected to the exhaust port, a' fluid pressure-actuated system adapted to be operated by uid pressure from the receiver, valve mechanisml associated with the intake of the compressor and comprising a chamber and a movable valve memberl y open position,

forming the movable wall of determined pressure to another the intermediate port will be on the other side therein for controlling the intake of the compressor, a spring for biasing the valve member to conduit means .for connecting the chamber to the exhaust side of the compressor. whereby a predetermined pressure built up by the compressor'will be eective to move the valve member to closed position, means forming an exhaust passage from the chamber, valve means including a slidable element for controlling the conduit means and the exhaust passage, a spring for biasing the'el'ement 'to a position Where the conduit means will be closed and the exhaust passage open, said element being movable by a. predeterminedl fluid pressure to another position where the conduit means will be open and the exhaust passage closed.

14. In apparatus of the class described, a iluid compressor provided with an intake port and an exhaust port, -a iluid pressure receiver connected to the exhaust port, a iluid pressure-actuated system adapted to be operated by uid pressure from the receiver, valve mechanism associated with the intake of the compressor and comprising a chamber and a movable valve-member therein for controlling the intake of the compressor, a spring for biasing the valve member to open position, a second chamber having a port intermediate its ends in-communication with the rst chamber, conduit means for placing the second chamber in communication with the exhaust side of the compressor, conduit means forv placing the second chamber in communication with the atmosphere, a piston in said second chamber and a spring for biasing said piston to a position where the intermediate port will be on one side of the lpiston and in communication with the atmosphere onlyfsaid piston being moved by a preposition where of the piston and in communication with the exhaust side of the compressor.

15. In apparatus of the class described, a fluid compressor provided with an intake port and an exhaust port, a fluid pressure receiver connected to the exhaustport, a iluid pressure-actuated system adapted to be operated by fluid pressure from the receiver, a casing having a passage in communication with the intake port, a chamber in the casing, a'movable valve member in the chamber and adapted to control the passage, a

spring for biasing the valve member to open position, conduit means for connecting the chamber to the receiver, means forming a relief passage from the chamber, and valve means operable by iluid pressure from the fluid-actuated system-for causing a release of the iluid under pressure in the chamber.

' FRED H. STROUP. 

